What evidence can be observed to determine when a chemical reaction takes place? (List all
6)
If a mixture contains 75% of one compound and 25% of its enantiomer, what is the e.e. of the mixture
Answer: The enantiomeric excess ee is 50%
Explanation:
Given that;
compound A = 75%, B = 25%
ee = ?
so
ee = [( A - B) / ( A + B)] × 100
= [( 75 - 25) / ( 75 + 25)] × 100
= [50 / 100] × 100
= 0.5 × 100
= 50%
Therefore enantiomeric excess ee is 50%
HELP I need these 2 questions answered
Answer:
1=a 2=d i think
Explanation:
The elements in a column of the periodic table *
have similar properties
are in the same period
have the same atomic mass
have very similar chemical symbols
Answer:
have similar properties
Explanation:
Elements in a column of the periodic table have similar chemical properties.
A periodic column is also called a group or family.
Chemical properties are determined by the valence electrons. The number of valence electrons determines how atoms chemically combine.Elements in the same group has the same number of valence electrons.
Therefore, they will combine chemically the same way.
This is not so for the periods on the periodic table.
How does the sun transfer energy through space to the earth
is the prime meridian a longitudinal or latitudinal line?
Answer:
longitudinal
Explanation:
A prime meridian is the meridian (a line of longitude) in a geographic coordinate system at which longitude is defined to be 0°. Together, a prime meridian and its anti-meridian (the 180th meridian in a 360°-system) form a great circle. This great circle divides a spheroid into two hemispheres.
Sb2S3 + 3Fe --> 2Sb + 3FeS
When 0.022mol Sb2S3 react with an excess of Fe, 0.08mol Sb is produced. What is the percent yield of
this reaction? (hint: what's the theoretical yield?)
The actual value is greater than the theoretical value
Further explanationGiven
Reaction
Sb2S3 + 3Fe --> 2Sb + 3FeS
0.022 mol Sb2S3
0.08mol Sb
Required
The percent yield
Solution
Percent yield is the comparison of the amount of product obtained from a reaction(actual) with the amount you calculated (theoretical)
General formula:
Percent yield = (Actual yield / theoretical yield )x 100%
Theoretical yield of Sb : 2/1 x 0.022 mol = 0.044 moles
In the question, there seems to be an error, because the actual yield value(0.08=?) should be smaller than the theoretical yield(0.044)
A reference point is an object or location from which the movement of another object is determined. Which of the following could be
a reference point?
I. a house
II. a moving car
III. a point on a map
IV. a person
A. I,III and IV only
B. I, II, III, and IV
C. Ill only
D. I and III only
Answer:
C. Ill only
Explanation:
Motion can be defined as a change in location with respect to a reference point.
This ultimately implies that, motion would occur as a result of a change in location (position) of an object with respect to a reference point or frame of reference i.e where it was standing before the effect of an external force.
Mathematically, the motion of an object is described in terms of acceleration, time, distance, speed, velocity, displacement etc.
A reference point is an object or location from which the movement of another object is determined.
Thus, a point on a map is considered to be a reference point because it represents the starting point of an object or person in motion.
How many grams are in one mole of carbon?
Answer: In one mole of carbon, we get 12g of carbon
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Mass data for reaction of NaHCO3-Na2CO3 mixture with HCL:
Mass of crucible and cover (g) 28.8258
Mass of crucible, cover and mixture (g) 29.4948
Mass of crucible, cover and residue after reaction with HCL (g)
1st weighing... 29.4454
2nd weighing... 29.4455
Required:
Calculation of percent composition of NaHCO3 and Na2CO33 in an unknown mixture
For the element Lithium give the number of bonds it would like to form with other atoms.
A)1
B)2
C)3
Answer: A) 1
Explanation:
Lithium is the third element of the periodic table with atomic number of 3. The atomic number is equal to the number of electrons for a neutral atom and thus there are 3 electrons in Lithium.
The electronic configuration of Lithium (Li) is [tex]1s^22s^1[/tex]. Thus it can gain one electron to complete its octet and attain stability. Thus it can form one bond with other atoms.
Example: Lithium can form one bond with flourine to form LiF by losing one electron to form [tex]Li^+[/tex].
Biological polymers are made up of individual monomers that are linked together by bonds. The major types of biological polymers are nucleic acids, proteins, and polysaccharides. Complete the sentences.
Nucleic acids are polymers of________
Proteins are polymers of_________
Polysaccharides are polymers of________
Answer:
1. Nucleotides
2. Amino acids
3. Monosaccharides
Explanation:
There are four major biological polymers in nature namely: carbohydrate (polysaccharides), lipids, proteins and nucleic acids. These polymers are formed from smaller units called MONOMERS, which are linked together via chemical bonds. The monomeric units of the polymers are listed below:
- Carbohydrates or polysaccharides are polymers of monomers called MONOSACCHARIDES linked by glycosidic bonds.
- Nucleic acids are polymers of monomers called NUCLEOTIDES linked by phosphodiester bonds.
- Proteins are polymers of monomers called AMINO ACIDS linked by peptide bonds.
How many grams are in 5.2 moles of Potassium?
Explanation:
203.31 brainliest
Answer:
203.31g when rounded to 2 decimal places.
If today is October 7th and we observe a waxing gibbous, on what date will we observe the next waning crescent?
Answer:
14 days.
Explanation:
If today were October 7 and we observed a waxing gibbous moon, that is, a moon with an illumination greater than a first quarter but less than a full moon, we would have to wait 14 days to see a waning crescent moon, which would be a moon with a visibility less than the last quarter but greater than a new moon.
What determines the type of air mass that forms in an area?
Answer:
Air masses are also identified based on whether they form over land or over water. Maritime air masses form over water and are humid. Continental air masses form over land and are dry. ... One that forms over the Indian Ocean is called a maritime tropical air mass and is warm and humid
The type of air mass that forms in an area is determined by the location and nature of the water and land.
What is meant by Air mass?Air mass may be characterized as a huge volume of air that is present in the atmosphere which possesses a uniform temperature and moisture. This attribute is generally classified on the basis of latitude and continental or maritime source regions.
For example, Maritime air masses construct over water and are significantly humid. While continental air masses construct over land and are significantly dry. That is why air masses are characterized by the temperature and humidity of the given region.
Therefore, the type of air mass that forms in an area is determined by the location and nature of the water and land along with the temperature and humidity of the given region.
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How many molecules of malic acid (C4H6O5), an acid found in apples and other fruits, are there in 1.25 g
Answer:
5.61 * 10²¹ molecules
Explanation:
You have 1.25 g of malic acid, C4H.Os, an acid found in apples and other fruits. How many molecules of the acid do you have?
Solution:
A molecule is the group of two or more atoms held together by chemical bonds.
The number of molecules is calculated using the formula:
number of molecules in a substance = number of moles of substance * Avogadro constant
Avogadro constant = 6.02 * 10²³ mol⁻¹
number of moles = mass / molar mass
Given that mass = 1.25 g
molar mass of malic acid (C₄H₆O₅) = (12 * 4) + (1 * 6) + (16 * 5) = 48 + 6 + 80 = 134 g/mol
number of moles = mass / molar mass = 1.25 g / 134 g/mol = 0.0093 mol
Recall that: number of molecules in a substance = number of moles of substance * Avogadro constant
number of molecules in a substance = 0.0093 mol * 6.02 * 10²³ mol⁻¹ = 5.61 * 10²¹ molecules
convert 0.00028 to scientific notation
Answer:
2.8 x10^-4
Explanation:
. What is the percent by mass of iron in the compound Fe2O32 The molar mass Fe2O3 is 159,69 g/mol. of
Answer:
Percent by mass is 69.42% Fe
Explanation:
If the molar mass is 159.69 grams per mol, and our goal is to find the percent by mass of iron, then we need to find the mass of iron first. We will calculate the amu of Iron and divide that by the total molar mass of Fe2O3.. and then multiply by 100 and write with a % in order to find the percent by mass (percent composition)
Fe2 = 2(55.845) = 111.69
111.69/159.69 = 0.69941762164
0.69941762164 * 100 = 69.42% Fe
The study of chemicals is called chemistry.
The correct answer to the question is Percent by mass is 69.42% Fe
What is a molecule?A molecule is an electrically neutral group of two or more atoms held together by chemical bonds. Molecules are distinguished from ions by their lack of electrical charge.If the molar mass is 159.69 grams per mole, and our goal is to find the percent by mass of iron, then we need to find the mass of iron first.
We will calculate the AMU of Iron and divide that by the total molar mass of Fe2O3. and then multiply by 100 and write with a % in order to find the percent by mass (percent composition)
[tex]Fe2 = 2(55.845) = 111.69\\\\\\frac{111.69}{159.69} = 0.69941762164\\\\0.69941762164 * 100 = 69.42% Fe[/tex]
Hence, the correct option answer is 69.42.
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5.How many moles of uranium are in 50 grams of uranium?
The price of gold is $40.63/g. How many kg of gold would be worth $100?
Answer:
0.00246kg
Explanation:
1g = $40.63
$100 = $100/40.63 = 2.46g
2.46/1000 g = 0.00246kg
Violet has found a container of aluminum
bromide that says it contains 1.28 moles of
AlBr 3. What is the mass of this sample of
aluminum bromide? Please round your
answer to two digits after the decimal point,
and remember to include correct, complete
units (including substance formula).
Answer:
69
Explanation:
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1.28 moles of aluminum bromide (AlBr₃) has a mass of 341.35 g.
We want to convert 1.28 moles of aluminum bromide (AlBr₃) to grams. We will need first to calculate its molar mass.
What is the molar mass?The molar mass is the sum of the total mass in grams of all the atoms that make up a mole of a particular molecule.
Step 1: Calculate the molar mass of aluminum bromide.M(AlBr₃) = M(Al) + 3 M(Br) = 26.98 g/mol + 3 × 79.90 g/mol =
= 266.68 g/mol
Step 2: Convert 1.28 moles to mass.1.28 mol × 266.68 g/mol = 341.35 g
1.28 moles of aluminum bromide (AlBr₃) has a mass of 341.35 g.
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Helpppppp pleaseeeee with 16
Answer:
Neither accurate nor precise
Explanation:
The measurements shown on the table are neither accurate nor precise in value.
Accuracy is the nearness of the measured value to the true value.
Precision is the ability to reproduce a result.
From the given problem, we find that the true value is 1.52 and the average of the readings is not even close. So, it is not accurateAlso, there is no repeatability of the readings, so the work lacks precision. Therefore, this result is neither precise nor accurate.What are the two types of alleles? A: Dominant and recessive B: genotype and phenotype C: Gene and chromosome or D: Gene and DNA
Answer:
dominant and recessive
Explanation:
1) What is the mass of 6.2 mol of K2CO3?
Answer:
[tex]\boxed {\boxed {\sf 856.8648 \ grams \ of \ K_2CO_3}}[/tex]
Explanation:
To convert from moles to grams, we must find the molar mass.
1. Molar Mass
First, identify the elements in the compound. K₂CO₃ It has potassium, carbon, and oxygen. Find these elements and their masses on the Periodic Table.
K: 39.098 g/mol C: 12.011 g/mol O: 15.999 g/molNote the subscript of 2 after K and 3 after O. We must multiply oxygen's molar mass by 2, then oxygen's by 3, and add carbon.
2(39.098 g/mol) + 3(15.999 g/mol) + 12.011 g/mol= 138.204 g/mol2. Convert Moles to Grams
Use the molar mass as a fraction.
[tex]\frac {138.204 \ g \ K_2CO_3}{1 \ mol \ K_23CO_3}[/tex]
Multiply by the given number of moles: 6.2
[tex]6.2 \ mol \ K_2CO_3 *\frac {138.204 \ g \ K_2CO_3}{1 \ mol \ K_23CO_3}[/tex]
[tex]6.2 *\frac {138.204 \ g \ K_2CO_3}{1 }[/tex]
[tex]6.2 * {138.204 \ g \ K_2CO_3}[/tex]
[tex]856.8648 \ g \ K_2CO_3[/tex]
There are 856.8648 grams of potassium carbonate in 6.2 moles.
In order to become stable in an ionic bond, oxygen needs to (A) gain 2 electrons (C) share 2 electrons B) lose 2 electrons
Answer:
gains 2 electrons. In order for the new ionic compound to form a a neutral compound, the oxygens must gain 6 electrons
Answer:
C
Explanation:
because you got to share
CHEMISTRY!! Please help!!
Answer:
Yes, because it follows the octet rule.
Explanation:
The Lewis is correct
because it follows the octet rule.
And
The octet rule states that atoms tend to form compounds in ways that give them eight valence electrons and thus the electron configuration of a noble gas.
Suppose a current of is passed through an electroplating cell with an aqueous solution of agno3 in the cathode compartment for seconds. Calculate the mass of pure silver deposited on a metal object made into the cathode of the cell.
The given question is incomplete. The complete question is:
Suppose a current of 0.920 A is passed through an electroplating cell with an aqueous solution of agno3 in the cathode compartment for 47.0 seconds. Calculate the mass of pure silver deposited on a metal object made into the cathode of the cell.
Answer: 0.0484 g
Explanation:
[tex]Q=I\times t[/tex]
where Q= quantity of electricity in coloumbs
I = current in amperes = 0.920 A
t= time in seconds = 47.0 sec
[tex]Q=0.920A\times 47.0s=43.24C[/tex]
[tex]AgNO_3\rightarrow Ag^++NO_3^-[/tex]
[tex]Ag^++e^-\rightarrow Ag[/tex]
96500 Coloumb of electricity electrolyzes 1 mole of Ag
43.24 C of electricity deposits =[tex]\frac{1}{96500}\times 43.24=0.00045moles[/tex] of Ag
[tex]\text{ mass of Ag}={\text{no of moles}\times {\text{Molar mass}}=0.00045mol\times 108g=0.0484g[/tex]
Thus the mass of pure silver deposited on a metal object made into the cathode of the cell is 0.0484 g
The number of light waves that occur in one second is known as the wave's
Question 2 options:
amplitude
frequency
energy
movement
Answer:
b
Explanation:
I did this quiz and i think a got it right i also looked up my answer to make sure it was right good luck on quiz :)
Energy that is shifted from warmer to cooler temperatures between two substances
1. Heat
2. Potential Energy
3. Thermal Energy
4. Kinetic Energy
Answer:
1) Heat
Explanation:
Heat Transfer: The movement of heat from a warmer object to a colder one
How many moles of gold, Au, are in 3.60 x 10^-5 g of gold?
1.83 × 10⁻⁷ mol Au
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisExplanation:Step 1: Define
3.60 × 10⁻⁵ g Au (Gold)
Step 2: Identify Conversions
Molar Mass of Au - 196.97 g/mol
Step 3: Convert
Set up: [tex]\displaystyle 3.60 \cdot 10^{-5} \ g \ Au(\frac{1 \ mol \ Au}{196.97 \ g \ Au})[/tex]Multiply: [tex]\displaystyle 1.82769 \cdot 10^{-7} \ mol \ Au[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
1.82769 × 10⁻⁷ mol Au ≈ 1.83 × 10⁻⁷ mol Au